12c Agents not showing up on list for upgrade

If you are trying to find your agent to upgrade but it is not in the list you need to check the "Not Upgradable Agents".

1. Go to Setup>Manage Cloud Control>Upgrade Agents
2. Click "Not Upgradable Agents"
3. Following the recommendation to fix the issue
4. Once resolved try to upgrade the agent again.

Another way to check "Not Upgradable Agents"

1. Go to Setup>Manage Cloud Control>Agents
2. Click the link "Not Upgradable"
3. Review the reason